Japanese Journal of Clinical Toxicology
Online ISSN : 2758-2140
Print ISSN : 0914-3777
Case Reports
A case of valproic acid overdose with delayed hyperammonemia due to carnitine deficiency
Yukari MiyoshiKoichiro SueyoshiYuki NakamuraTadashi IshiharaYutaka KondoKen OkamotoHiroshi Tanaka
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2022 Volume 35 Issue 4 Pages 313-318


A 15-year-old female patient was transported to our hospital due to altered consciousness after valproic acid (VPA) overdose. She attempted suicide by taking 18 g of sustainedrelease VPA 19 hours before arrival. On admission, she was in a comatose state, her serum NH3 level was high (723 μg/dL), and her serum free carnitine level was low (12.1 mmol/L). Oral intubation, administration of activated charcoal and levocarnitine, and continuous hemodiafiltration were performed. The serum levels of VPA and NH3 decreased immediately. She regained consciousness on day 3 and was discharged on day 9 with no sequelae. Patients with overdose of sustained-release VPA need to be observed for a longer time and carnitine administration should be considered for hyperammonemia.

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© 2022 Japanese Society for Clinical Toxicology
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